Telegraph system.



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JOHN H. BELL, OF SOUTH ORANGE, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEWYOIRK.

TELEGRAPH SYSTEM.

Specification of Letters Patent. Patented B1 11 1919 Application filed April 22, 1918. Serial No. 230,193.

' To all whom it may concern:

Be it known that I, JOHN H. BELL, a

citizen of the United States, residing at South Orange, in the county of Essex, State of New Jersey, have invented certain new and useful Improvements in Telegraph Systoms, of which the following is a full, clear, concise, and exact description.

This invention relates to telegraph systems and more particularly to telegraph transmitter systems.

ther provides that the line conductor will.

be connected to the earth during periods intermediate the beginning and ending of an impulse and also during intervals corresponding with spacing periods between impulses.

This invention is illustrated diagrammatically in the accompanyingdrawing in which for the sake of clearness, only so much of a telegraph system has beenshown as will be necessary to a clear understanding of the features of this invention.

' In the drawing, Figure 1, is shown a transmitting equipment suitable for transmission of telegraphic signals in accordance with the features of this invention; in Fig. 2 is shown a theoretical form of impulse intervals which correspond in the matter of time with a circuit controlling device, the operations of which initiate the sending of impulses. .In Fig. 3 is shown, in theoretical form, the electrical effects established by signaling impulses in a line conductor. An alternate arrangement shown in Fig. 4 may be substituted for the arrangement shown in Fig. 1. V

In describing the operation of this system, reference character L indicates a line conductor which is connected to a movin contact member of relay 1 A source 0 positively poled and grounded current 2 is con nected through a winding 3 of this relay, thence by way of normal contacts 5, of a transmitting key 4, to complete circuit through a polarized relay 6, and a condenser 7 to earth. Relay 1 may be of a neutral type, the armature of which is normally retracted to establish its contacts 8 as shown in the drawing, thereby completing a circuit from the line L to earth. The polar relay 6 may be of a non-biased type, that is, its armature will remain in the position to which it may have been moved by an impulse of currentuntil an impulse of current in the opposite direction, through the winding of the relay, biases the armature to the other side. In the positions in which the circuits are-shown in the drawing, it will be clear that circuit for an impulse of positive current is completed through the relay 1, key 5, and relay 6, as already traced, will have established a positive bias of the relay 6, whereby its contacts 9 will continue closed until the key 4 may be operated.v If

now the key 4 is depressed its contacts 5 will beseparated, while its contacts 11 will be closed. A circuit may now be traced from a negativelypoled and grounded battery 12, through a winding 13 of the relay. 1, contacts 11 of the key 4, thence through the winding of the relay 6 and the condenser 7 to earth. Thisimpulse of negative current will bias the armature of the polar relay 6 to close its contacts 14, thereby completing a circuit from a negatively poled line or cable battery 15 to the contacts of the relay 1. The impulse of current just traced throughthe winding 13 will cause the relay 1 to momentarily attract its armature, thereby separating its contacts 8 to disconnect the line L from-earth and to connect it over the contacts 16 of this relay with the battery 15. The period during-which the contacts 16 of the relay 1 may remain closed is relatively short and corresponds with the time constants of the circuit with respect to the capacity eiiect in the condenser 7 and the battery 10 over the relay contacts 9 and the denser, line terminal circuits including a plurality of oppositely poled current sources and contacts of said polar relay, and. contacts controlled by said neutral relay for connecting said line circuit to earth during periods that no change of current eflects are taking place in said condenser.

2. n a telegraph transmitting system, a line circuit, a neutral relay, a polar relay and a condenser, sources of current, transmitting means for selectively connecting difierent current polarities through acircuit formed by said relays and condenser, means controlled by said polar relay for selecting different current polarities to be controlled by said neutral relay, and means controlled by said neutral relay for rendering said selected polarities efiective with the line circuit during moments current effects are active in said condenser.

3. In a telegraph transmitting system, a line circuit, a plurality of current sources, a compound wound relay, a polar relay, a transmitting key for alternately connecting different windings of said compound wound relay in series with said sources of current and said polar relay, a condenser included in said circuit, and means jointly controlled by said relays for momentarily connecting said sources of current with said line con ductor to effect signaling.

4.'In a telegraph system, a line circuit, sources of current, a compound Wound re lay, a polar relay, a condenser, a transmitting means for selectively connecting said sources of current through difierent Windings of said compound wound relay, said polar relay and said condenser, means controlled by said polar relay for selectin different polarities from said sources 0 current, and means controlled by said compound wound relay for connecting said line circuit either to earth or to the current polarities selected by said polar relay.

5. In a telegraph transmitting system, a line circuit, a local circuit comprising a compound wound relay, a transmitting key, a polar relay, a condenser and sources of oppositely poled currents, a terminal circuit for said line comprising an earth connection, pluralities of oppositely poled current sources and contacts of said polar relay, and means controlled by said compound wound relay for alternately connecting said line circuit over said earth connection or the terminal circuit controlled by said polar relay in a manner corresponding with the operation of said transmitting key in controlling the operation of said relays.

In witness whereof, I hereunto subscribe my name this 15th day of April, A. D. 1918.

JOHN H. BELL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, .D. G. 

